13 Jun
2012
13 Jun
'12
2:04 a.m.
On Jun 12, 2012, at 6:02 PM, Chuck Guzis wrote:
On 12 Jun 2012 at 20:43, Tony Duell wrote:
I am missing something here... The OP says that adding 3 bits to a 16
bit word is enough to be able to correct any single-bit error.
I think he meant +1 instead of -1 in the equation. So 5 bits, not 3.
But I assumed that he'd just copied it wrong from memory or source.
Faulty memory, in this case. I suppose I could use some ECC in the
wetware myself. :-)
- Dave
> Seems excessive... I seem to recall you need
log2(n) - 1 bits,
> which would be 3 bits (32-bit ECC needs 4 bits).
Doesn;t that assume the 'extra' bits are known to be correct.
Those can be in error too (even if the'real' data bits are
correct),
No, it doesn't. See Wikipedia's Hamming code page (asking for
SECDED redirects to it) for a brief treatment of the subject, or any
of many more detailed treatments of coding theory for more.